A semiconductor apparatus often operates in a number of different operating environments. Different operation modes may be associated with one or more of the different operating environments. In many cases, the semiconductor apparatus uses an operation mode setting circuit to set the operation mode of the semiconductor apparatus.
An operating environment may be defined by a number of different operation parameters. Examples of such operation parameters include, but are not limited to, a cycle time of an external clock cycle supplied to the semiconductor apparatus, an external temperature of the semiconductor apparatus, an internal temperature of the semiconductor apparatus and a power supply voltage supplied to the semiconductor apparatus.
In many cases, one or more of the operating parameters that define the operating environment of the semiconductor apparatus varies.